Electrical device manufacturers are challenged with trying to offer several wiring methods to an installer of switches and receptacles while at the same time trying to maintain a small device. Hot, neutral, and ground conductors are affixed to an electrical device using one of three methods: side wiring, back wiring, and speed wiring. In side wiring, the bare end of the conductor is wrapped a half turn around a terminal screw post and the screw head is tightened, trapping the conductor between the screw head and the terminal. The conductor must be wrapped in a clockwise direction so that tightening the screw doesn't unwrap the conductor from the screw post. Back wiring is similar to side wiring except that a pressure plate is positioned between the screw head and the terminal. The bare end of the conductor is trapped between the pressure plate and the terminal as the screw is tightened. In speed wiring, the bare end of the conductor is inserted into a hole of the body of the switch or receptacle, where the conductor is captivated by a terminal spring arm.
Problems occur when trying to devise a pressure plate which accommodates all three types of wiring on a narrow body device.